The production of neurons is typically confined to the developmental period. In contrast, the hippocampal region continues to produce new granule neurons in adulthood in a variety of mammals ranging from rodents to primates. Recent studies have shown that hippocampal-dependent learning, trace eyeblink conditioning and spatial navigating learning, promotes the survival of adult-generated neurons in the dentate gyrus. However, the neuroanatomical and molecular characteristics of neurons rescued by learning remain unknown. The main objective of this proposal is to characterize the role of learning in the survival, differentiation and integration of adult-generated neurons within the mammalian hippocampal region. Using techniques to label newly generated cells combined with in situ hybridization and retrograde tract-tracing, we will investigate the molecular and cellular impact of associative learning on adult-generated neurons in the rat. The realization of this aim will further our understanding of the relationship between adult neurogenesis and learning and may provide insight into the regenerative potential of mammalian nervous tissue and the mechanisms underlying neurodegenerative disease.